This invention relates to a document searching method for changing over between plural document databases, and constructing relationships between plural document databases.
As more and more document information is converted to electronic format, a greater need is emerging to search different types of document database simultaneously. For instance, users often wish to look up dictionaries relating to newspaper articles which they may find of interest.
In the past, it was possible to perform a search independently by changing over between plural document databases, but there was no way of examining the relevancy of sets of documents in other databases to a set of documents in one particular database.
If however the search is limited to the same document database, it is possible to search other document sets within that database. In this case, sufficient search speed is often obtained by calculating the relevance between documents before searching. Even with different databases, it is possible to search plural document databases at the same time if such a calculation is performed beforehand, but since the need for calculation increases as the number of databases increases due to increasing numbers of combinations, this method is not realistic.
It is also possible to first analyze the set of key documents on the user side to compose a search input, and then search in other document databases by using the input, but in this case, the user side has to receive all the information about the set of key documents, and if the document databases are on a network, the amount of traffic would be huge.